The planned project is a continuation of work in progress. Nonocclusive intestinal ischemia will be produced in the pig by shock after pericardial tamponade. Pericardial tamponade will be released, and the animals followed for one to three days. Angiography will be performed before, during, and at 24, 48, and 72 hours after shock. Pigs will be sacrificed, and angiographic and histologic correlations determined. The value of papaverine infusion into the superior mesenteric artery in protecting against NII will be determined. Mesenteric venous blood will be assayed for oxygen saturation, and levels of acid phosphatase, and ribonuclease, before, during, and at 24 hours after production of NII. A model for production of nonocclusive colonic ischemia will be attemped, using moderate systemic hypotension and localized colonic distention.